Network Working Group T. Dierks
Request for Comments: 4346 Independent
Obsoletes: 2246 E. Rescorla
Category: Standards Track RTFM, Inc.
April 2006
The Transport Layer Security (TLS) Protocol
Version 1.1
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2006).
Abstract
This document specifies Version 1.1 of the Transport Layer Security
(TLS) protocol. The TLS protocol provides communications security
over the Internet. The protocol allows client/server applications to
communicate in a way that is designed to prevent eavesdropping,
tampering, or message forgery.
Dierks & Rescorla Standards Track [Page 1]RFC 4346 The TLS Protocol April 2006Table of Contents
1. Introduction ....................................................4
1.1. Differences from TLS 1.0 ...................................5
1.2. Requirements Terminology ...................................5
2. Goals ...........................................................5
3. Goals of This Document ..........................................6
4. Presentation Language ...........................................6
4.1. Basic Block Size ...........................................7
4.2. Miscellaneous ..............................................7
4.3. Vectors ....................................................7
4.4. Numbers ....................................................8
4.5. Enumerateds ................................................8
4.6. Constructed Types ..........................................9
4.6.1. Variants ...........................................10
4.7. Cryptographic Attributes ..................................11
4.8. Constants .................................................12
5. HMAC and the Pseudorandom Function .............................12
6. The TLS Record Protocol ........................................14
6.1. Connection States .........................................15
6.2. Record layer ..............................................17
6.2.1. Fragmentation ......................................17
6.2.2. Record Compression and Decompression ...............19
6.2.3. Record Payload Protection ..........................19
6.2.3.1. Null or Standard Stream Cipher ............20
6.2.3.2. CBC Block Cipher ..........................21
6.3. Key Calculation ...........................................24
7. The TLS Handshaking Protocols ..................................24
7.1. Change Cipher Spec Protocol ...............................25
7.2. Alert Protocol ............................................26
7.2.1. Closure Alerts .....................................27
7.2.2. Error Alerts .......................................28
7.3. Handshake Protocol Overview ...............................31
7.4. Handshake Protocol ........................................34
7.4.1. Hello Messages .....................................35
7.4.1.1. Hello request .............................35
7.4.1.2. Client Hello ..............................36
7.4.1.3. Server Hello ..............................39
7.4.2. Server Certificate .................................40
7.4.3. Server Key Exchange Message ........................42
7.4.4. Certificate request ................................44
7.4.5. Server Hello Done ..................................46
7.4.6. Client certificate .................................46
7.4.7. Client Key Exchange Message ........................47
7.4.7.1. RSA Encrypted Premaster Secret Message ....47
7.4.7.2. Client Diffie-Hellman Public Value ........50
7.4.8. Certificate verify .................................50
7.4.9. Finished ...........................................51
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